GPT-5.3 Codex vs Gemini 3.1 Pro Preview
| OpenAI GPT-5.3 Codex | Google Gemini 3.1 Pro Preview | |
|---|---|---|
| Vendor | OpenAI | |
| Context window | 400,000 | 1,048,576 |
| Max output | 128,000 | 65,536 |
| Reasoning | Yes | Yes |
| Tool calling | Yes | Yes |
| File input | Yes | Yes |
| Input | text, image, file | text, image, video, audio, file |
| Output | text | text |
| Released | 2026-02-05 | 2026-02-19 |